1. Field of the Invention
The present invention generally relates to junction boxes, organizers and distribution units for fiber optic cables and associated interconnection devices, and more particularly to a fiber optic housing having a novel construction which yields a low part-count, with many pans manufactured inexpensively from sheet metal.
2. Description of the Prior Art
Organizers and distribution units for optical fiber cables are known in the art, and are commonly used for the direct interconnection of pairs of optical fibers, or the cross-connection of a pair of fibers using an intermediate pigtail or jumper fiber. These devices can also be used to store excess fiber slack. When used for connection purposes, they commonly house various interconnection devices such as optical splices or connectors, for both discrete fiber pairs and multi-fiber ribbons (see, e.g., U.S. Pat. Nos. 4,792,203, 4,824,196, 5,093,887 and 5,247,603). The term "splice" usually refers to the permanent attachment of a pair of fiber ends, while the term "connector" usually refers to a device which allows for the detachment and re-attachment of the fibers; these terms should not, however, be construed in a limiting sense inasmuch as the present invention applies to fiber optic housings which receive any type of interconnection devices, including splices, connectors, couplers, splitters, etc.
As the use of optical fiber spreads, there is a growing need for housing designs which are low cost, particularly for telecommunications applications. For example, the designs disclosed in the above-mentioned patents, while rich in features, all require a large number of components, some difficult to fabricate, and an excessive number of mechanical fasteners to join the components in the fully assembled product. This not only adds to the cost of the pans, but also increases assembly time (whether in the factory or the field), and disassembly is often impractical. Several constructions require the use of special tools. Rudimentary housing designs may achieve lower cost, but they lack the flexibility in operation that is desired by major telecommunications providers.
Most conventional designs are also inadequate regarding installation of the fiber optic cables and interconnection devices. For example, most fiber distribution units provide access only through the front panel. Some designs allow removal of the top, but limited to the uppermost panel of the housing, and do not allow access at the sides. Many other prior art designs do not allow simultaneous back and front plane access. Finally, in most systems it is difficult to completely test the installation without fully positioning all components in the housing, which in turn makes it more difficult to fix a faulty installation since the cabling and connectors must then be removed from the housing (possibly several times). It would, therefore, be desirable to devise a fiber optic housing which has a reduced part count and overall simplification of component fabrication and attachment, to minimize cost as well as assembly time, and yet provide flexibility during installation and inspection of the cables and connectors. It would in particular be advantageous to allow near complete installation of the system for testing purposes while still providing full access to the managed area.